frontier

• 名词，指两个地区之间的边界或边陲，也指已开发或已探索区域的边缘，常与扩张或探索相关。

A noun referring to a boundary or border between two regions, or the edge of a settled or explored area, often associated with expansion or discovery.

1. Border between countriesB1formal

   A line or border separating two countries, especially a remote or less developed area.

   边境

   • The soldiers guarded the frontier between the two nations.
   • They crossed the frontier into the neighboring country.
   • The frontier was heavily patrolled by border guards.

   同义词borderborderlineboundarydividing linepartition

2. Unexplored areaB2formal

   The extreme limit of settled land or knowledge beyond which lies the unknown.

   未开发的前沿

   • Space exploration represents the final frontier for humanity.
   • Scientists are pushing back the frontiers of medical research.
   • The American frontier was a place of adventure and opportunity.

   同义词backwoodsborderboundaryedgefringelimitperipheryunknownvergewilderness

3. Leading edge of developmentB2formal

   The most advanced or recent stage of development in a particular field.

   前沿

   • This technology is at the frontier of artificial intelligence.
   • The company is working on the frontier of renewable energy.
   • They are exploring new frontiers in quantum computing.

   同义词cutting edgeforefrontleading edgevanguard